Not available in Community Designer

You can read only lists, however (see Multivalue Fields).

	Note
	Reading maps is handled as reading pure string (for all data types as map's values).

    ...
    <attendees>John</attendees>
    <attendees>Vicky</attendees>
    <attendees>Brian</attendees>
    ...

    <Mapping xpath="attendees" cloverField="attendanceList"/> 
    

If you use input port reading in discrete or source mode, you can map particular input fields to output fields using inputField attribute.

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<Context xpath="/rootPath" outPort="0">
 	<Mapping cloverField="field2" inputField="field2"/>
</Context>

This example shows the basic usage of XMLReader.

You have a retail.xml file with data about your retail sale.

<?xml version="1.0" ?>
<orders>
 	<order id="1">
 	 	<firstname>John</firstname>
 	 	<surname>Smith</surname>
 	 	<emails>
 	 	 	<email>[email protected]</email>
 	 	 	<email>[email protected]</email>
 	 	</emails>
 	 	<item>
 	 	 	<goodName>table</goodName>
 	 	 	<items>1</items>
 	 	</item>
 	</order>
 	<order id="2">
 	 	<firstname>Ellen</firstname>
 	 	<surname>Smith</surname>
 	 	<emails>
 	 	 	<email>[email protected]</email>
 	 	</emails>
 	 	<item>
 	 	 	<goodName>chair</goodName>
 	 	 	<items>3</items>
 	 	</item>
 	 	<item>
 	 	 	<goodName>tablecloth</goodName>
 	 	 	<item>2</item>
 	 	</item>
 	</order>
</orders>

Create a list containing order_id, customer firstname, surname and email(s).

Solution

Create a metadata having 4 fields: order_id (integer), name (string), surname (string), email (string[]).

Set up attributes File URL, Implicit mapping and Mapping.

If you set Implicit mapping to true, fields name and surname are populated by values of corresponding elements.

Content of Mapping attribute:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<Context xpath="/orders/order" outPort="0">
 	<Mapping cloverField="order_id" xpath="@id"/>
 	<Mapping cloverField="email" xpath="./emails/email"/>
</Context>

The XMLReader will send following 2 records to it's first output port.

1  John   Smith  [[email protected], [email protected]]
2  Ellen  Smith  [[email protected]]

This example shows reading input file while some input fields are mapped to output.

Given a list of customers and paths to the files with orders.

C001|./file001.xml
C002|./file002.xml

Each file can contain one or more products:

<?xml version="1.0" ?>
<products>
 	<product>A</product>
 	<product>B</product>
</products>

Create a list with customers and products:

C001|A
C001|B
C002|E

Solution

Use File URL, Charset, and Mapping attributes.

<?xml version="1.0" encoding="UTF-8" standalone="no"?>

<Context xpath="/products/product" outPort="0">
 	<Mapping cloverField="productID" xpath="."/>
 	<Mapping cloverField="customerID" inputField="ID"/>
</Context>

This example shows reading input file with nested elements. The nested elements on different levels are sent out to the different output ports.

The input file countries-and-counties.xml contains list of countries. Each country has a name and contains several counties. Each county has a name.

<?xml version="1.0"?>
<countries>
 	<country>
 		<name>England</name>
 		<county>
 			<name>Bristol</name>
 		</county>
 		<county>
 			<name>Cumbria</name>
 		</county>
 		<county>
 			<name>Devon</name>
 		</county>
 	</country>
 	<country>
 		<name>Scotland</name>
 		<county>
 			<name>Edinburgh</name>
 		</county>
 		<county>
 			<name>Fife</name>
 		</county>
 	</country>
</countries>

Make a list of countries, and make a list of counties with corresponding countries.

Solution

Assign metadata country with field countryName to the edge on the first output port.

Assign metadata county with fields countryName and countyName to the edge on the second output port.

Use File URL, Charset, and Mapping attributes.

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<Context xpath="/countries/country" outPort="0">
 	<Mapping cloverField="countryName" xpath="name"/>
 	<Context xpath="./county" outPort="1">
 	 	<Mapping cloverField="countryName" xpath="../name" />
 	 	<Mapping cloverField="countyName" xpath="name"/>
 	</Context>
</Context>

The records sent to the first output port are:

England
Scotland

The records sent to the second output port are:

England	 | Bristol
England  | Cumbria
England  | Devon
Scotland | Edinburgh
Scotland | Fife

This example shows you way to read xml that contains different namespaces.

A web page contains svg graphics and links to other web pages. The links (<a>) are of two namespaces: xhtml and svg. Get URLs of links that are from svg image.

<html xmlns="http://www.w3.org/1999/xhtml">
 	<head>
 	</head>
 	<body>
 	 	<svg width="1024" height="768"
 	 	     xmlns="http://www.w3.org/2000/svg" version="1.1"> 
 	 	 	<a href="http://www.cloveretl.com">
 	 	 	 	<circle cx="512" cy="384" r="80"/>
 	 	 	</a>
 	 	</svg>
 	 	<p>
 	 	 	<a href="http://www.example.com">www.example.com</a>
 	 	</p>
 	</body>
</html>

Solution

Use File URL, Charset, and Mapping attributes.

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<Context xpath="/xhtml:html//svg:a"
 	     namespacePaths='xhtml="http://www.w3.org/1999/xhtml";svg="http://www.w3.org/2000/svg"'
 	     outPort="0">
 	<Mapping cloverField="field1" xpath="@href"/>
</Context>

The output contains on URL:

http://www.cloveretl.com

To avoid typing lines like:

<Mapping xpath="salary" cloverField="salary"/>

Switch on the implicit mapping and use explicit mapping only to populate fields with data from distinct elements.

The <Context> element should be used only if you intend to send record corresponding to subtree to the output.

Use

<Context xpath="/elem1/elem11" outPort="0">
	<Mapping cloverField="field1" xpath="elem111"/>
</Context>			

instead of

<Context xpath="/elem1">
	<Context xpath="elem11" outPort="0">
		<Mapping cloverField="field1" xpath="elem111"/>
	</Context>
</Context>			

We recommend users to explicitly specify Charset.

XMLReader is available since CloverETL 3.3.x.

As of Clover 3.3, reading multivalue fields is supported - you can read only lists, however (see Multivalue Fields).

Since Clover 4.1.0-M1 you can assign values of fields from input port to fields on output port.